The invention relates to an apparatus for individually removing sheets from a stack of sheets, for example, paper or the like, including a sheet stack support member and several power driven sheet separating roller sets. More specifically, the invention relates to an apparatus for guiding and supplying individual sheets from a stack through an office machine and out again onto a sheet receiving stack.
Sheet separating devices for paper sheets or the like are well known. These devices supply the sheets to office machines, such as printers, duplicators, copiers or to other types of processing. Prior art devices are constructed in such a manner that they must be adjusted precisely to the particular type of paper thickness employed for any particular type of operation. If it is necessary to change to another paper thickness a careful new adjustmment must be made. The required adjustments make the conventional paper feeders or sheet separators expensive and subject to trouble which may occur, because the adjustment has changed during the operation. Further, the adjustments are time consuming.
In many office machines it is customary to use interfolded, continuous sheets of paper or sets of office form. This is, for example, the case in automatic typewriters, accounting machines, and data processing machines. Such continuous, interfolded forms are provided with a row of apertures running along one edge or margin of the sheet for assuring a line true feed advance of the sheet in the machine. After the continuous sheets have passed through the office machine, they are separated from each other, and it is necessary to remove the margin of apertured strip. This involves additional labor and may even require additional machines which can remove the margin. Thus, these machines have the common disadvantage that pre-printed letterheads, invoice forms, and the like, which are available as individual sheets only, cannot be used in this type of machine which makes it necessary to have these forms and letterheads prepared especially for use in the just described type of machine. U.S. Pat. No. 3,963,110 describes a storage magazine and sheet feeder for a typing apparatus such as a tape driven typewriter, wherein the tray for supplying new sheets and the tray for receiving the typed up sheet extends at a steep angle above the typewriter platen, presumably, to take advantage of gravity for feeding the sheets to the typewriter platen. However, while this may be advantageous as far as the sheet supply is concerned, it is not desirable as far as the sheet removal is concerned because the sheets have to be driven against gravity up again. Moreover, there is no assurance in this type of feeder that only one sheet at a time or one set of sheets at a time will be supplied to the platen regardless of the thickness of the sheet or set of sheets.
Similar considerations apply to the paper feeder according to U.S. Pat. No. 3,430,748 which is coordinated with the platen in a typewriter which also does not assure that one and only one sheet or one set of sheets will be supplied to the platen.